Ethanol has been in the capital district area for about two or three years. We see various problems with ethanol as it affects our outboard motors and generators. We have seen a dramatic increase in the number of fuel-related problems with our Yamaha outboard motors since 2006. While these problems are not specific to Yamaha motors, I will focus on them because that is the primary brand that we service.
Ethanol is an additive used to keep the octane number (i.e. 87) where it should be. In the past MTBE was used to do this. It was found that MTBE was harmful to ground water and it is no longer used. Ethanol cleans the fuel supply chain. Ethanol attracts water. Gas with ethanol does not has have as much power as gas used to have. Ethanol can "eat" resins and older non-compatible fuel tanks, hoses and gaskets.
So why ethanol? $$$COST$$$, and it is plentiful.
We see ethanol effect motors in three main ways. Fuel contamination from ethanol cleaning the fuel supply chain, fuel contamination from the ethanol attacting water, and phase separation.
The cleansing of the fuel supply chain has been the biggest problem we have seen so far. When the ethanol is introduced into the fuel supply it cleans everything from the tanker truck to the in ground tanks to the fuel pumps to the boat tank, hoses, filters and carburetor bowls, jets, and passages. In the past carbs needed to be cleaned due to fuel being left in the bowl for extened period of time. The fuel would "varnish" the bowls and gum up jets and passages. Recently we have not seen that type of problem as much as we used to. Today's issues seem to be with debris being brought to the carburetor through the cleaning process caused by ethanol.
More to follow...